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220 Chapter 7 • Study Guide

Lesson 1 Our planet of Life• Ecologists break down an area’s overall biodiversity into

three major categories: species diversity, genetic diversity, and ecosystem diversity. Species diversity is the number or variety of species in a particular area. Genetic diversity describes the differences in DNA among individuals of a population or species. Ecosystem diversity refers to an area’s variety of ecosystems, communities, or habitats.

• Biodiversity varies among taxonomic groups and geo-graphic regions.

• Biodiversity enables ecosystems to provide economically valuable services and products, such as clean water, food crops, medicines, and recreation areas.

biodiversity (200) species diversity (201) genetic diversity (202) ecosystem diversity (202)

Lesson 2 extinction and Biodiversity Loss• Scientists monitor biodiversity closely and have noticed

significantly higher than normal extinction rates in recent decades. Endangered species are at serious risk of extinc-tion. Threatened species are likely to become endangered soon throughout all or part of their range.

• Habitat change and loss, invasive species, pollution, and overharvesting are the major causes of biodiversity loss. Climate change is also a factor and may become a greater one in the future.

extirpation (207) endangered species (208) threatened species (208) habitat fragmentation (209) poaching (211)

Lesson 3 protecting Biodiversity• Nations can pass laws (such as the Endangered Species

Act) and sign international treaties (such as CITES) that protect biodiversity.

• Species Survival Plans manage, protect, and reintroduce threatened and endangered species.

• Strategies that manage whole ecosystems and habitats, such as the hotspot approach, conservation concessions, and wildlife corridors, protect many species at once. The hotspot approach involves focusing conservation efforts on areas with especially high numbers of endemic species that are rapidly losing biodiversity. Conservation conces-sions are agreements in which countries are paid to protect their natural resources. Wildlife corridors connect habitat fragments, enabling populations to interbreed.

Endangered Species Act (ESA) (212) captive breeding (214) Species Survival Plan (SSP) (214) biodiversity hotspot (215) endemic (215)

InquIry LABs And ActIvItIes• Exploring Plant Diversity Mark an outdoor area and classify the variety of plant

life there. Then calculate the plant diversity of the area.• Overharvesting Using a method of scooping beans that models trawl-

ing, try to catch your “target fish species” without harming the “protected species.”

• Endangered Species Is there a species near you that is endangered? Find out

what’s being done to increase the current population.

Why is it important to protect biodiversity?

Lesson 2 Why is global

biodiversity decreasing?

Lesson 1 What is biodiversity?

Lesson 3 How can we protect

and preserve biodiversity?

STUDY RESOURCES

Chapter 7 Self Test • Chapter 7 Worksheets • Chapter 7 Overview Presentation (for PowerPoint)

Biodiversity and Conservation 221

The Central Case in this chapter explored efforts that brought the Siberian tiger back from the brink of extinction. All over the world, scientists are trying to slow the loss of our planet’s biological diversity. Based on what you have learned, do you think that all nations should be responsible for protecting biodiversity? Explain. Use examples from the Central Case and the lesson to support your answer.

7. The illegal capture or killing of an organism, often for money, is called

a. poaching. c. fragmentation. b. harvesting. d. extinction.

8. Which of the following forbids the U.S. govern-ment and its citizens from harming endangered or threatened species and their habitats?

a. the Environmental Protection Agency b. Species Survival Plan c. the Endangered Species Act d. the Convention on International Trade in En-

dangered Species

9. Some conservation biologists focus on areas where the greatest number of unique species can be protected with the least amount of effort. These areas are called

a. wildlife corridors. b. habitat fragments. c. biodiversity hotspots. d. conservation concessions.

10. The eastern long-beaked echidna, shown here, is an egg-laying mammal found only in New Guinea. Which of the following terms describes an organism such as the echidna that is found in one place and nowhere else in the world?

a. endemic c. endangered b. threatened d. conserved

Review Concepts and Terms 1. Which of the following is NOT part of overall

biodiversity? a. species diversity c. individual diversity b. genetic diversity d. ecosystem diversity

2. The tiger (Panthera tigris), jaguar (Panthera onca), and lion (Panthera leo) are all members of the same

a. subspecies. c. genus. b. species. d. ecosystem.

3. What provides the raw material for adaptation to local conditions?

a. ecosystem diversity c. extirpation b. species diversity d. genetic diversity

4. Which of the following increases species diversity?

a. extirpation c. extinction b. speciation d. poaching

5. The disappearance of a particular population from a given area, but not of the entire species globally, is called

a. extinction. c. extirpation. b. immigration. d. speciation.

6. Globally, the leading cause of biodiversity loss is a. invasive species. b. poaching and overharvesting. c. pollution. d. habitat change and loss.

Answers

Chapter Assessment For answers to the Chapter Assessment, see page A–10 at the back of the book.

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Data from Millennium Ecosystem Asssessment. World Resources Institute, Washington, D.C. Categories used in this figure are modified from the source so as to match the biome categorization used in this book.

Habitat Loss by Biome100

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Tropical r

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222 Chapter 7 • Assessment

Modified True/False Write true if the statement is true. If it is false, change the underlined word or words to make the statement true.

11. Biodiversity tends to decrease nearer the equator. 12. Threatened species are at the highest risk of

extinction. 13. Climate change can have global, not just local,

impacts on biodiversity. 14. The process of breeding and raising organisms in

controlled conditions is called cloning.

Reading Comprehension Read the following selection and answer the questions that follow.The latitudinal gradient influences the species diversity of Earth’s biomes. Tropical dry forests and rain forests tend to support far more species than tundra and boreal forests, for instance. It seems likely that plant productivity and climate stability are at least partially responsible for this pattern. Greater amounts of solar energy, heat, and humidity at tropi-cal latitudes lead to more plant growth, making areas nearer the equator more productive and able to support larger numbers of animals. Further, the rela-tively stable temperatures and rainfall of equatorial regions favor organisms with specialized niches that do particular things very well. Thus, many species can divide up resources and coexist in tropical areas.

15. An appropriate title for this passage might be a. “Describing Biomes” b. “Is There a Latitudinal Gradient?” c. “Explaining the Latitudinal Gradient” d. “Why Is Biodiversity Decreasing?”

16. From the passage, it is possible to infer that a. rain forests are found closer to the equator than

boreal forests. b. boreal forest has the lowest biodiversity of any

biome. c. rainforest animals are larger than animals that

live in boreal forests. d. boreal forest animals never divide resources.

Analyze DataThe graph below shows habitat loss across the world’s biomes. The green portion of the bars indicates the habitat lost up to 1950. The magenta portion of the bars indicates habitat lost between 1950 and 1990. Together, the magenta and green represent the total habitat lost up to 1990. Use the data to answer the questions.

17. Interpret Graphs Which of the biomes shown lost more than half of their habitat by 1990?

18. Interpret Graphs Which three of the biomes shown in the graph lost the most habitat by 1950? Between 1950 and 1990? Total up to 1990?

19. Infer Why do you think that some biomes have experienced so much more habitat loss than others?

20. Predict If you were to update this graph to in-clude habitat lost between 1990 and today, what do you think the data would show? You may wish to look back at the biome map in the chapter Biomes and Aquatic Ecosystems.

Ecological Footprints

You

Your class

Your hometown

Your state

United States

Population Total Hectares ofLand Used

Hectares of Forest Used

Data from Living Planet Index. 2008. World Wildlife Fund International, Switzerland.

Biodiversity and Conservation 223

3. Today, in the United States there are about 302 million hectares of forests. That is about 33 percent of the total land area. If the population of the United States remains stable, and if we do not regrow any forest we cut down, how many generations will it take to completely use up our forested land?

4. What is the connection between land use and biodiversity?

Read the information below. Copy the table into your notebook, and record your calculations. Then, answer the questions that follow.

Habitat loss is a leading cause of biodiversity loss today. The World Wildlife Fund, Zoological Society of London, and Global Footprint Network released their Living Planet Report in 2008. According to the report, the American ecological footprint was 9.5 hectares (23.5 acres) per person in 2005. Of that, approximately 1.02 hectares (2.5 acres) were forest. Given this infor-mation, fill in the footprint table. 1. Other ecological footprint categories noted by the

Living Planet Report include cropland and grazing land. They calculate that 1.38 hectares of cropland and 0.30 hectare of grazing land are required to sup-port the average American. How many total hect-ares of cropland and grazing land does that add up to for the current population of the United States?

2. The uses for cropland and grazing land are obvious—they provide food. But what about forest? One of the largest uses for forest is timber for hous-ing. What are some other uses for forest?

Short Answer 21. What is biodiversity? 22. What are ecosystem services? Give two examples. 23. What is the difference between ecotourism and

tourism? 24. What are mass extinctions? 25. Are all non-native species invasive? What makes a

species invasive? 26. What is a biodiversity hotspot? How does an area

qualify to be a hotspot?

Critical Thinking 27. Form an Opinion Ecotourism can have both ben-

eficial and harmful effects on an area. Describe these effects, and then explain whether you would support ecotourism in your area.

28. Apply Concepts Some scientists think that we are in the middle of the “sixth mass extinction.” What does that mean? What evidence do they use to support that claim?

29. Relate Cause and Effect What is the relation-ship between biodiversity loss, medicine, and agriculture?

30. Explain What happens when a top predator, such as the Siberian tiger, is removed from an ecologi-cal system?

31. Apply Concepts How does the Endangered Species Act protect biodiversity?

32. Propose a Solution Suppose you are a town plan-ner. There has been huge growth recently. Several new housing subdivisions are sprouting up at the edge of town where there was once forest. What suggestions can you make to ensure minimal impact on the local species?

Write About It 33. Creative Writing What could happen if more

nations do not take steps to prevent habitat loss? Write a letter from the future. Describe what has become of some of the world’s species and ecosystems.

34. Apply the BIGQUESTION Most scientists think there is a strong connection between biodiversity loss and increasing human population size. How do you think an increased number of people affect biodiversity in your area? Consider each of the major causes of biodiversity loss in your answer.